1. Higher Compression Ratio: Diesel engines operate with much higher compression ratios (typically 14:1 to 25:1) compared to gasoline engines (typically 8:1 to 12:1). This higher compression significantly increases the pressure and temperature inside the cylinder before combustion. This higher pressure translates directly into greater force on the piston, resulting in more torque. Gasoline engines rely on a spark to ignite the fuel-air mixture, which limits the achievable compression ratio due to the risk of pre-ignition.
2. Fuel Characteristics: Diesel fuel has a higher energy density and a longer burn duration than gasoline. The longer burn duration produces a more consistent pressure curve during the power stroke, resulting in smoother torque delivery across the engine's RPM range. The higher energy density means more energy is released per unit of fuel, contributing to the overall torque output.
In simpler terms: Diesel engines squeeze the air much more tightly (higher compression) and then inject fuel into that highly compressed, hot air. This leads to a powerful, controlled explosion that pushes the pistons harder and for longer, generating greater torque. Gasoline engines, on the other hand, rely on a spark to ignite a less compressed mixture, resulting in a less powerful explosion and lower torque.
